We propose a randomized feasibility and early outcomes trial to compare gastric bypass, gastric banding, and a structured weight loss program induced by diet and increased physical activity for the treatment of type 2 diabetes mellitus (T2DM) in moderately obese patients. There has been a dramatic increase in the number of bariatric procedures performed in the last decade and bariatric surgery has been reported to result in significant changes in glucose metabolism in T2DM that often results in complete resolution of diabetes in many patients. Yet there remain many unanswered questions that require well-controlled studies to more completely inform health care decision making and clinical practice in this area. For example, it is not clear, whether diabetes is influenced by the type of surgery or by the amount of weight lost or if bariatric surgery is more effective than non-surgical weight loss induced by diet and physical activity in T2DM patients with more moderate BMIs (Class I and Class II obesity). Finally comparing the improvements in cardiovascular risk factors such as insulin resistance, cardio-respiratory fitness, hypertension and inflammation between surgical to non-surgical weight loss has not been well investigated. The primary aim of this proposal is to determine the feasibility of performing a randomized trial comparing two major types of bariatric surgery, gastric bypass and gastric banding, versus a structured weight loss program induced by diet and increased physical activity in patients with Class I and II obesity and T2DM. A secondary aim is to obtain preliminary information regarding the effectiveness of various bariatric surgery procedures versus an intensive behavioral intervention to induce weight loss with diet and increased physical activity. Finally, we will explore the feasibility, methods for, and implementation of a range of early outcome measures including;resolution of diabetes, beta cell function, change in metabolic parameters, body composition, physical activity, and several psychosocial measures. The importance of this pilot study will be to provide crucial information necessary to plan a larger, more comprehensive and more long-term multi-center trial to further address critical unanswered questions in this emerging area. PUBLIC HEALTH RELEVANCE: The proposed project will address the lack of randomized controlled studies and comparative effectiveness research in bariatric surgery by utilizing a three arm randomized trial to compare surgical and non-surgical treatments for Type 2 diabetes in obese subjects. Understanding more clearly the impact of bariatric surgery compared to a non-surgical, intensive lifestyle intervention for the treatment of diabetes in the setting of obesity will have a major impact on both the science and public health for the communities of obese and diabetic patients in this country and worldwide.